Police in Dresden, Germany are on the hunt for at least two suspects after a break-in at the Grünes Gewölbe museum (also commonly known as the Green Vault) resulted in the theft of around 100 pieces of royal jewels and jewelry. The officials say that the items were of “immeasurable worth,” including a 648-carat sapphire that was once a royal gift from Russia’s Tsar Peter the Great. According to German media outlets, this theft represents the biggest incident of its kind since World War II.

Despite the heist’s apparent success and the high value of what was stolen, the theft itself seems a bit more like something you’d see from the Joker in Christopher Nolan’s Batman movies than the sort of stuff you’d get from the “Ocean’s 11” crew: Authorities were first alerted to the theft when a fire broke out in an electrical distribution box associated with the museum and which investigators now believe was set intentionally to disable the museum’s alarm system. Despite the lack of power, surveillance cameras continued to run, capturing footage of two men inside the museum.

There were security guards on duty at the time, but they reportedly called police rather than intervening, as that is the museum’s established procedure for this sort of crime. The guards were reportedly unarmed.

In order to gain access to the building, the two men only had to cut through a fence, remove an iron grill, and break a window. Once inside, they simply smashed through the cases holding three sets of jewels and jewelry — each set is made up of 37 individual pieces — and made off with them.

“The suspects came in through a window, and walked towards a glass vitrine, smashed it and left, they disappeared,” Dresden police Chief Criminal Director Volker Lange said.

Officials are still working to assess just what exactly was stolen and what is total value may be, but according to statements made by the museum, the priceless artifacts were apparently not insured.

“We are shocked by the brutality of the burglary,” Marion Ackermann, the director of the State Art Collections, said.

Police were notified of the robbery at approximately 5 a.m. on Monday and soon assigned 16 patrol cars to the vicinity to scour the area for the thieves, who reportedly escaped by car shortly before the police arrived. A burned car was eventually found in the area, though police are thus far unsure if it was related to the heist or was merely a coincidence. Investigators have also pointed out that, although only two men are seen in the footage, they have not discounted the possibility that a number of others may have been involved and assisted in their escape. According to police, it would take just minutes for the thieves to have reached the highway from the museum.

Some of the stolen pieces are so well known that Ackermann wonders if they could even be sold at all, so it seems likely that diamonds and gems would be broken up or reshaped prior to being sold, which could make it impossible to recover them.

“This is a bitter day for the cultural heritage of Saxony. The thieves stole cultural treasures of immeasurable worth — that is not only the material worth but also the intangible worth to the state of Saxony, which is impossible to estimate,” Saxony’s interior minister, Roland Wöller, said.